Targeting the path of Nominal Gross Domestic Product (NGDP) is probably the most “fashionable” solution proposed for dragging the developed world’s economies out of depression. This post will refer to the UK, but lots more work has been done on the US from this perspective, particularly by Scott Sumner and David Beckworth. Britmouse has blogged about NGDP from a UK perspective.
Real GDP is a proxy for our incomes adjusted for inflation, how well off we are. Nominal GDP is the same but refers to our incomes in cash terms. This nominal measure deviating from trend has been what has driven the wild swings in employment and production the developed world has seen since 2007.
NGDP matters because wages and debt are sticky.
Wages: NGDP can decrease if all other prices decrease with it, the relative prices between them will not change and apart from updating some menus nothing will have really changed. But it is incredibly hard to cut wages, look at the clustering of wage changes around zero in the below graph (via Paul Krugman). This means a decrease in NGDP relative to wages will throw people out of work as employers become unwilling to employ them at the prevailing nominal wage.
Debt: We care about what real resources we can consume but all our contracts are written in nominal terms. If I owe someone £10,000 then at some point I have to hand over some bits of paper, or packages of electrons, to someone for that amount. But, if NGDP grows below trend the total nominal size of the economy will be smaller than expected when I took out the debt, but the size of my debt will not. The real cost of my debt will have increased and this will work to depress the economy because this dynamic will affect a number of people.
If NGDP sinks below trend there are then at least two mechanisms which can act to depress an economy.  Has it sunk below trend? Yes it has.
Is off trend NGDP growth associated with weak real GDP growth? Yes it is.
Are changes from trend NGDP correlated with changes in employment? Yes they are.
Let me tell you a story with a different ending to the one you know. The year 2007 began with NGDP growing to trend, and employment decreasing against the backdrop of international inflationary pressures and financial distress. NGDP reversed course and began to decline during the second quarter of 2007 as did employment, crucially this was before the Lehmann Brother’s bankruptcy and the ohmygodwereallgoingtodie stage of the financial crisis. Unemployment had already increased by nearly 200,000 after NGDP began declining but before the financial crisis began in earnest.
This doesn’t exhonerate any bankers, they put the Bank and Treasury in this position after all. But it does imply different priority for actions. Occupy Threadneedle Street, my friends, not the London Stock Exchange.
Looking at the third graph you can see NGDP decline, recovery and stagnation correlating closely with decline, (mild) recovery and stagnation in UK employment. The Bank of England controls the country’s printing presses and hence the nominal economy and responsibility for this depression lies with the Monetary Policy Committee for doing too little to avert it and with the Treasury for doing so little to force them to do more.
In the UK and US the last couple of decades have seen NGDP grow at about 5% a year, and this nominal growth has been split between price increases and economic growth. In 2008 NGDP collapsed and we saw deflation, disinflation, and recession. To date NGDP has not yet recovered to trend, in fact it remains over 10% below trend – and this is our main problem.
Increase NGDP and employment, incomes and taxes would increase, many intractable problems would vanish (though many would not). There are risks and there are methodological problems, but there huge gains for everyone if they right policy is adopted and I want to do my part to try and make sure the right policy is adopted.
 Data from here, I’ve used basic prices to strip out the effect of VAT jumping up and down